The McGovern Commission changes to the convention rules marginalized the influence of establishment Democratic figures (some of whom had lost the nomination to McGovern). Many refused to support him, with some switching their support to the incumbent President Richard Nixon through a campaign effort called "Democrats for Nixon". This also had the effect of leaving the McGovern campaign at a significant disadvantage in funding compared to Nixon.

In addition, McGovern was repeatedly attacked by associates of Nixon, including the infamous Watergate break-in, which eventually led to Nixon's resignation in 1974.

Party disunity